[tgreenstein]

I've never seen any software that does this specifically. Some routing applications (Garmin Mobile XT, for example) will allow you to point to your current location on the map, which then gives the GPSr a "headstart" on figuring out your exact location (if the GPSr knows roughly where you are it will have a good idea of which satellites should be visible).

Once you've gotten your first fix, though, subsequent TTA (time to acquisition) should be much shorter.

On your second question: I don't know if you need GPSGate for navigation purposes. Google Maps will give you simple directions by itself (of course, it won't speak those directions -- you'll have to look at the display) but Google Maps is not a very effective navigation solution (unless you've got a copilot who will read you the instructions while you're driving!).